JP5179064B2 - Chip resistor manufacturing method and chip resistor - Google Patents

Description

  The present invention relates to a chip resistor manufacturing method and a chip resistor.

  Despite the fact that the resistor paste material used in the manufacture of chip resistors is expensive, in order to meet the various resistance values required in the market, a resistor paste with various resistivities has been prepared in the past. The printing film thickness has been finely controlled by changing the screen printing conditions. However, the resistance value range that can be controlled by changing the printing conditions is very narrow, and as a result, the initial resistance value before trimming does not fall within the target resistance value range and must be discarded.

  In recent years, there is a demand for a chip resistor with a resistance value of about 10 mΩ for current detection and a small change in resistance value due to temperature. Therefore, it has been difficult to realize a chip resistor having a low resistance value and a small resistance value change due to temperature.

  Furthermore, in recent years, there is a demand for a chip resistor having excellent surge resistance and a small size, but with conventional screen printing technology, the line width of the pattern is limited to 100 to 150 μm by printing, drying and firing of the resistance paste. . The surge resistance characteristics of chip resistors can be improved by increasing the resistance pattern and reducing the electric field intensity per unit length. However, it is difficult to make the resistance pattern meandering longer with a small chip resistor. Met.

In recent years, there has been a demand for miniaturization and low profile of multi-chip resistors along with miniaturization and weight reduction of electronic devices. There is a need to reduce so-called crosstalk noise that becomes noise. Since the conventional multiple chip resistor forms a plurality of resistors only on the upper surface of the substrate, it is difficult to increase the interval between the resistors.
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  The present invention solves the above-mentioned problems, and a first object thereof is to realize a chip resistor having various resistance values with one type of paste.

  A second object is to realize a chip resistor having a low resistance value and a small change in resistance value due to temperature.

  A third object is to realize a small chip resistor having excellent surge resistance.

  A fourth object is to realize a multiple chip resistor that is small and low in profile and has low crosstalk noise.

The invention according to claim 1 is a step of producing a plurality of types of insulating substrates that differ only in the depth of the meandering groove-shaped recess formed on the upper surface of the substrate ;
A step of embedding a resistor in the recess to substantially the same height as the upper surface of the substrate, a step of forming a pair of upper surface electrodes electrically connected to both ends of the resistor, and a protection covering at least the resistor A method of manufacturing a chip resistor including a step of forming a film, the method including a step of selecting one type of insulating substrate from the plurality of types as a method of adjusting a resistance value .

The invention according to claim 2 is a step of producing a plurality of types of insulating substrates which are formed on the upper surface of the substrate and differ only in the depth of the meandering groove-shaped recess ;
Burying a resistor higher than the upper surface of the substrate in the recess;
Polishing the surface of the embedded resistor to make the surface of the resistor substantially flush with the upper surface of the substrate;
Manufacturing of a chip resistor having a step of forming a pair of upper surface electrodes electrically connected to both ends of the resistor, and a step of forming a protective film covering the resistor and a part of the upper surface electrode A method,
The method for adjusting the resistance value includes a step of selecting one type of insulating substrate from the plurality of types.

According to the first aspect of the present invention, a plurality of types of insulating substrates differing only in the depth of the groove-shaped recess are prepared, and the resistor is embedded in the recess up to the surface of the insulating substrate. Thus, the thickness of the resistor on the insulating substrate can be changed according to the type of the insulating substrate. For this reason, the chip resistor which has many types of resistance values can be manufactured using one type of resistor paste.

In addition, since the resistor is embedded in the recess, it is possible to prevent bleeding and sagging during printing, drying, and firing of the resistor paste.
Further, since the concave pattern is formed by press work before firing the substrate, shape control including the depth direction is easy, and a target resistance value can be obtained without trimming.
Further, by deepening the groove of the concave pattern, it is possible to provide a chip resistor having a low resistance value that cannot be realized by the conventional technology.

According to the second aspect of the present invention, the resistor embedded in the recess higher than the upper surface of the substrate is polished so that the surface of the resistor and the upper surface of the substrate are flush with each other, so the thickness of the resistor embedded in the recess Exactly matches the depth of the recess. For this reason, the resistance value of the resistor can be set more accurately based on the difference in the depth of the recess.
In addition, since the accuracy required for the mask for screen printing used for embedding is remarkably low, efficient production becomes possible.

According to the first and second aspects of the invention, since the concave portion in which the resistor is embedded is meandered, it is possible to form a long resistance pattern having a narrow line width of, for example, 50 to 100 μm. . For this reason, a small chip resistor having excellent surge resistance can be manufactured.
In addition, by changing the depth and path length of the concave pattern, the initial resistance value before trimming can be easily controlled to be doubled or tripled. A value can be obtained, and a highly controllable manufacturing process can be realized.
Also, the contact area between the resistor and the substrate can be made much larger than before, and as a result, the heat dissipation is improved, and it is possible to provide a chip resistor having a larger rated power with the same chip area. .
In addition, it is possible to provide a chip resistor having a high resistance value that cannot be realized by the conventional technique by increasing the path length by forming a fine pattern.

A method for manufacturing a chip resistor according to a first embodiment of the present invention will be described below with reference to the accompanying drawings. As shown in FIGS. 1 and 2, a plurality of primary slits 11 are formed at equal intervals on a large insulating substrate 10 and a plurality of secondary slits 12 are formed at equal intervals. At the same time, a groove-shaped recess 13 extending from one end of the substrate to the other end is formed in the central portion of the strip-shaped substrate defined by the secondary slit 12 . The primary slit 11, the secondary slit 12, and the groove-shaped recess 13 are formed into a green sheet by press working and then fired, or the fired insulating substrate is processed with a rotating disk or laser light. When processing the groove-shaped recess 13 in the large-sized insulating substrate 10, a plurality of types of large-sized insulating substrates 10 having different depths of the groove-shaped recess 13 such as 15 μm and 30 μm are manufactured.

Next, as shown in FIG. 3, an electrode paste is printed and baked on the back surface of the large insulating substrate 10 to form a pair of lower surface electrodes 14.
3 to 8 show a chip piece 10A formed by dividing a large insulating substrate 10 from a primary slit 11 and a secondary slit 12 for convenience.

  Subsequently, as shown in FIG. 4, a resistor paste is formed by printing and baking a resistor paste in a large groove-like recess 13. When printing the resistance paste on the groove-shaped recess 13, the printing thickness of the resistance paste is adjusted so that the surface of the resistor 15 formed by firing the resistance paste is substantially flush with the surface of the insulating substrate 10. For example, a ruthenium oxide paste is used as the material of the resistance paste. Since the resistance paste is printed on the groove-shaped recess 13, it is possible to prevent bleeding and sagging from occurring at the edge, have an accurate width and thickness determined by the dimensions of the groove-shaped recess 13, and obtain a required volume when fired. be able to. Therefore, for example, if the resistance value of the resistor 15 is 20Ω when the insulating substrate 10 having a groove-like recess depth of 15 μm is used, the same resistance paste is used as the insulating substrate 10 having the groove-like recess 13 depth of 30 μm. When the resistor 15 is formed by printing and baking, a resistance value of 10Ω can be obtained.

Next, as shown in FIG. 5, the electrode paste to both ends of the resistor 15 by printing and baking to form a pair of upper surface electrodes 16.

  Next, as shown in FIG. 6, a protective film 19 is formed by printing and baking a glass paste so as to cover a part of the resistor 15 and both upper surface electrodes 16.

  After forming the protective film 19, as shown in FIG. 7, the large insulating substrate 10 is divided into strips from the primary slit 11, and electrode paste is printed and fired on both divided surfaces of the strip-shaped insulating substrate 10. The electrode 20 is formed. The electrode paste used as the side electrode 20 is printed so that the upper surface electrode 16 and the lower surface electrode 14 are electrically connected.

After the formation of the side electrode 20, the strip-shaped insulating substrate 10 is divided from the secondary slit 12 to form individual chip pieces 10A, and the upper electrode 16, the side electrode 20, and the lower electrode 14 of each chip piece 10A are plated with nickel. 21 and tin plating 22 are applied. FIG. 8 shows a schematic cross-sectional view of a chip resistor 10A manufactured by the manufacturing method according to the first embodiment.

  According to the present embodiment, a plurality of types of insulating substrates 10 having different depths of the groove-like recesses 13 are prepared, and the resistor 15 is embedded in the groove-like recesses 13 up to the surface of the insulating substrate 10. By selecting the type, the thickness of the resistor 15 on the insulating substrate 10 can be changed according to the type of the insulating substrate 10. For this reason, the chip resistor which has many types of resistance values can be manufactured using one type of resistor paste.

In addition, since the resistor 15 is embedded in the groove-shaped recess 13, it is possible to prevent bleeding and sagging during printing, drying, and firing of the resistance paste.
In addition, since the concave pattern is formed by pressing before firing the substrate, the shape control including the depth direction is easy, and the target resistance value can be obtained without trimming. If necessary, it is possible to form a cover coat and perform trimming to prevent a more accurate resistance value from being realized. In the first embodiment, the number of grooves is one. However, the present invention is not limited to this, and the initial resistance value can be changed by forming a plurality of grooves. In the first embodiment, the shape of the groove is an inverted trapezoid. However, the shape of the groove is not limited to this, and the initial resistance value can be changed by using an arbitrary shape such as a rectangular shape, a semicircular shape, a semi-elliptical shape, and a semi-oval shape. Further, in Embodiment 1, the shape of the groove is linear, but the initial resistance value can be changed by changing the length by meandering or the like. Needless to say, the initial resistance value can be changed by changing the width of the groove.
Further, by deepening the groove of the concave pattern, it is possible to provide a chip resistor having a low resistance value that cannot be realized by the conventional technology.

  A method for manufacturing a chip resistor according to a second embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 9, a primary slit 31 and a secondary slit 32 are formed on the surface of a large insulating substrate 30, and a groove-like recess is formed in each of the chip pieces 30A defined by the primary slit 31 and the secondary slit 32. 33 is formed. The groove-shaped recess 33 is formed to have a planar shape meandering in a substantially W shape. When the groove-shaped recess 33 is formed on the large-sized insulating substrate 30, a plurality of types of large-sized insulating substrates 30 having different depths of the groove-shaped recess 33 are manufactured as in the manufacturing method of the first embodiment. As types, for example, those having a depth of 10 μm and 20 μm of the groove-shaped recess 33 are prepared.

  Next, as shown in FIG. 10, an electrode paste is printed and baked on the back surface of the large insulating substrate 30 to form a pair of lower surface electrodes 34 for each chip piece 30A.

  Subsequently, as shown in FIG. 11, a resistor paste is formed by printing and baking a resistor paste in the groove-shaped recess 33. As shown in FIG. 12, the printing thickness of the resistance paste is adjusted so that the resistor 35 is slightly raised from the surface of the insulating substrate 30 at this time.

  After the formation of the resistor 35, a large insulating substrate 30 is set in the polishing apparatus 60 shown in FIG. The polishing apparatus 60 includes a polishing board 61 and a substrate holder 62 that moves up and down relative to the polishing board 61. A large-sized insulating substrate 30 is mounted on the substrate holder 62 so that the resistor 35 faces the polishing plate 61, and the substrate holder 62 is moved downward to remove the resistor 35 raised from the surface of the insulating substrate 30. Pressure contact. Then, the polishing board 61 is rotated to polish the raised resistor 35 so that the surface of the resistor 35 and the surface of the insulating substrate 30 are substantially flush with each other.

  Next, as shown in FIG. 14, an electrode paste is printed and baked on the polished large insulating substrate 30 to form a pair of upper surface electrodes 36 that are electrically connected to both ends of the resistor 35. Subsequently, a glass paste is printed and baked on the resistor 35 exposed between the upper surface electrodes 36 to form a cover coat layer 37.

  Then, a trimming groove 38 is formed in the resistor 35 by laser trimming from above the cover coat layer 37 to correct the resistance value of the resistor 35. As shown in FIG. 15, the trimming groove 38 is formed by notching so that the central notch 35 a of the resistor 35 meandering in a W shape extends in a direction parallel to the primary slit 31.

After the laser trimming, as in the manufacturing method according to the first embodiment, a protective film and side electrodes are sequentially formed, and nickel plating and tin plating are performed.
According to the present embodiment, the resistor 35 embedded in the groove-like recess 33 higher than the upper surface of the substrate 30 is polished so that the surface of the resistor 35 and the upper surface of the substrate 30 are flush with each other. The thickness of the buried resistor 35 exactly matches the depth of the groove-like recess 33. For this reason, the resistance value of the resistor 35 can be set more accurately based on the difference in the depth of the groove-shaped recess 33.

Further, since the groove-like recess 33 in which the resistor 35 is embedded is meandered, it is possible to form a long resistance pattern having a line width of 50 to 100 μm, for example. For this reason, a small chip resistor having excellent surge resistance can be manufactured.
In addition, by changing the depth and path length of the concave pattern, the initial resistance value before trimming can be easily controlled to be doubled or tripled. A value can be obtained, and a highly controllable manufacturing process can be realized.
Also, the contact area between the resistor and the substrate can be made much larger than before, and as a result, the heat dissipation is improved, and it is possible to provide a chip resistor having a larger rated power with the same chip area. .
In addition, it is possible to provide a chip resistor having a high resistance value that cannot be realized by the conventional technique by increasing the path length by forming a fine pattern.

  A method for manufacturing a chip resistor according to a third embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 16, 17, and 18, a row of groove-like recesses 43 is formed on the front and back surfaces of a chip piece 40 </ b> A defined by a primary slit 41 and a secondary slit 42 formed on a large insulating substrate 40. . In the present embodiment, each chip piece 40A is formed with a row of two groove-like recesses 43 on the front surface and the back surface. Each groove-like recess 43 is formed in parallel with the secondary slit 42. And the groove-shaped recess 43 on the front surface is not opposed to the groove-shaped recess 43 on the back surface, that is, the groove-shaped recess 43 on the back surface is arranged in the region between the groove-shaped recesses 43 adjacent to the front surface, and The groove-shaped recess 43 on the front surface is arranged in a region between adjacent groove-shaped recesses 43 on the back surface.

  Next, as shown in FIG. 19, the electrode paste is printed and baked on predetermined portions of the front and back surfaces of the insulating substrate to form the lower surface electrode 44. Each lower surface electrode 44 is provided on the surface opposite to the surface provided with the groove-shaped recess 43 so as to face each groove-shaped recess 43.

Subsequently, as shown in FIG. 20, a resistance paste 45 is formed by printing and baking a resistance paste in each groove-like recess 43. Next, as shown in FIG. 21, the electrode paste is printed and baked to form the upper surface electrode 46, and as shown in FIG. 22, the glass paste is printed and baked to form the cover coat layer 47, and laser trimming is performed. Thus, the trimming groove 48 is formed. Next, a protective film 49 is formed as shown in FIG. Subsequently, as shown in FIG. 24, a side electrode 50 is formed, and nickel plating and tin plating are performed. FIG. 25 is a cross-sectional view of the chip resistor manufactured by the manufacturing method according to this example. In the figure, 51 indicates nickel plating and 52 indicates tin plating.

According to the present embodiment, rows of groove-shaped recesses 43 are provided on both the front and back surfaces of the insulating substrate 40 and are arranged so that the groove-shaped recesses 43 on the front surface and the groove-shaped recesses 43 on the back surface do not face each other. Since the resistor 45 is embedded, the distance between the adjacent resistors 45 can be increased without reducing the number of the resistors 45 provided on the insulating substrate 40. For this reason, a multiple chip resistor with a small size, a low profile and a small crosstalk noise can be manufactured. In this embodiment, two groove-shaped recesses are provided on both the front and back surfaces of the insulating substrate.
In addition, although glass paste was used for the protective film in Examples 1, 2, and 3, it is not restricted to this, You may use resin paste. Moreover, although the baking silver paste was used for the side electrode, you may use not only this but a resin silver paste and a metal thin film.
Further, in Examples 2 and 3, laser trimming was performed after the cover coat layer 47 was formed in order to realize a precise resistance value, but it goes without saying that these steps may be omitted as in Example 1. Good.

It is a perspective view which shows the large-sized insulation board | substrate used for manufacture of the chip resistor which concerns on 1st Example of this invention. It is sectional drawing cut | disconnected from the 2-2 line | wire of FIG. It is a perspective view which shows the chip piece and lower surface electrode of the insulated substrate which comprise the chip resistor which concerns on 1st Example of this invention. It is a perspective view which shows the chip piece, a lower surface electrode, and a resistor. It is a perspective view which shows the chip piece, a lower surface electrode, a resistor, and an upper surface electrode. It is a perspective view which shows the chip piece, a lower surface electrode, a resistor, an upper surface electrode, and a protective film. It is a perspective view which shows the chip piece, a lower surface electrode, a resistor, an upper surface electrode, a cover coat layer, a protective film, and a side electrode. It is sectional drawing which shows the chip resistor which concerns on 1st Example of this invention. It is a perspective view which shows the large format insulated substrate used for manufacture of the chip resistor which concerns on 2nd Example of this invention. It is a perspective view which shows the chip piece and lower surface electrode of the insulated substrate which comprise the chip resistor which concerns on 2nd Example of this invention. It is a perspective view which shows the chip piece, a lower surface electrode, and a resistor. It is sectional drawing cut | disconnected from the 13-13 line | wire of FIG. It is explanatory drawing which shows the structure of the grinding | polishing apparatus used for manufacture of the chip resistor which concerns on 2nd Example of this invention. It is a perspective view which shows the chip piece which comprises the chip resistor which concerns on 2nd Example of this invention, a lower surface electrode, a resistor, an upper surface electrode, and a cover coat layer. It is a perspective view which shows the chip piece, a lower surface electrode, a resistor, an upper surface electrode, a cover coat layer, and a trimming groove. It is a perspective view which shows the large-sized insulation board | substrate used for manufacture of the chip resistor which concerns on 3rd Example of this invention. It is a perspective view which shows the chip piece of the insulated substrate which comprises the chip resistor which concerns on 3rd Example of this invention. It is sectional drawing cut | disconnected from the 19-19 line | wire of FIG. It is a perspective view which shows the chip piece and lower surface electrode of the insulated substrate which comprise the chip resistor which concerns on 3rd Example of this invention. It is a perspective view which shows the chip piece, a lower surface electrode, and a resistor. It is a perspective view which shows the chip piece, a lower surface electrode, a resistor, and an upper surface electrode. It is a perspective view which shows the chip piece, a lower surface electrode, a resistor, an upper surface electrode, and a cover coat layer. It is a perspective view which shows the chip piece, a lower surface electrode, a resistor, an upper surface electrode, a cover coat layer, and a protective film. It is a perspective view which shows the chip piece, a lower surface electrode, a resistor, an upper surface electrode, a cover coat layer, a protective film, and a side electrode. It is sectional drawing cut | disconnected from the 25-25 line | wire of FIG.

10, 30, 40 ... insulating substrates 10A, 30A, 40A ... chip pieces 11, 31, 41 ... primary slits 12, 32, 42 ... secondary slits 13, 33, 43 ... groove-like recesses 14, 34, 44 ... bottom electrodes 15, 35, 45... Resistors 16, 36, 46.
37 , 47 ... Cover coat layer
38 , 48 ... trimming grooves 19, 49 ... protective film 20, 50 ... side electrodes

Claims (2)

Producing a plurality of types of insulating substrates that differ only in the depth of the meandering groove-like recesses formed on the upper surface of the substrate ;
A step of embedding a resistor in the recess to substantially the same height as the upper surface of the substrate, a step of forming a pair of upper surface electrodes electrically connected to both ends of the resistor, and a protection covering at least the resistor A method of manufacturing a chip resistor comprising a step of forming a film, the method including a step of selecting one type of insulating substrate from the plurality of types as a method of adjusting a resistance value Method. Producing a plurality of types of insulating substrates that differ only in the depth of the meandering groove-like recesses formed on the upper surface of the substrate ;
Burying a resistor higher than the upper surface of the substrate in the recess;
Polishing the surface of the embedded resistor to make the surface of the resistor substantially flush with the upper surface of the substrate;
Manufacturing of a chip resistor having a step of forming a pair of upper surface electrodes electrically connected to both ends of the resistor, and a step of forming a protective film covering the resistor and a part of the upper surface electrode A method,
A method of manufacturing a chip resistor, comprising a step of selecting one type of insulating substrate from the plurality of types as a method of adjusting a resistance value .

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